Diplomacy by committee: Assessing resolve and costly signals in group settings

Abstract Assessing resolve and interpreting costly signals are crucial tasks for leaders engaging in international diplomacy. However, leaders rarely make these decisions in isolation, relying on advisers to help assess adversary intentions. How do group dynamics change the way costly signals are interpreted? We field a large‐scale group experiment to examine how assessments of resolve vary across group settings. We find groups make significantly higher initial assessments of adversary resolve than individuals do, but also update their beliefs less after receiving new information. In small group contexts, first impressions may play a stronger role in shaping beliefs than any signals—costly or otherwise—that come afterwards. This has important implications for our understanding of signaling, providing further evidence that costly signals are less straightforward than often assumed.